Following therapy, the majority of patients with AML and many patients with MDS will achieve a remission that is defined by the lack of any evidence of the disease when viewing bone marrow samples under a microscope. Despite the absence of disease by this method, many patients in remission will still have what is referred to as Minimal Residual Disease when more sensitive methods are applied. The presence of Minimal Residual Disease following therapy does not guarantee that the patient will experience a relapse. This is likely a result of the failure of these techniques to examine those cells that are responsible for disease relapse. Recent data suggests that in the majority of patients with AML or MDS only a minor population of the malignant cells are capable of maintaining the disease and are likely responsible for relapse following therapy. This minor population of cells can be identified by the proteins they have on their surface. This study tests the ability to identify Minimal Residual Disease following therapy by performing special assays that specifically target this minor population of malignant cells.